Bioscience of Microbiota, Food and Health最新文献

The gut microbiota resides in the human gastrointestinal tract, where it plays an important role in maintaining host health. Recent advancements in next-generation sequencing methods have revealed the link between dysbiosis (imbalance of the normal gut microbiota) and several diseases, as this imbalance can disrupt the symbiotic relationship between the host and associated microbes. Establishment of the gut microbiota starts in utero or just after birth, and its composition dramatically changes to an adult-like composition by 3 years of age. Because dysbiosis during childhood may persist through adulthood, it is crucial to acquire a balanced gut microbiota in childhood. Therefore, current studies have focused on the factors affecting the infant gut microbiota. This review discusses recent findings, including those from our studies, on how various factors, including the delivery mode, feeding type, and administration of drugs, including antibiotics, can influence the infant gut microbiota. Here, we also address future approaches for the prevention and restoration of dysbiosis in children.

Ogimi is one of Japan's longevity villages and is located in Okinawa Prefecture. In this study, we focused on the elderly women living in the village, classified them into two groups based on whether or not they lived in Ogimi during the first 3 years of their lives, and compared the gut microbiota between the two groups. There were no differences in alpha and beta diversity; however, we found that the elderly women who lived in Ogimi during the first 3 years of their lives had a higher rate of Akkermansia muciniphila colonization in their guts.

Although bifidobacteria are already widely used as beneficial microbes with health-promoting effects, their amino acid utilization and metabolism are not yet fully understood. Knowledge about the metabolism of sulfur-containing amino acids in bifidobacteria is especially limited. In this study, we tested the methionine utilization ability of several bifidobacterial strains when it was the sole available sulfur source. Although bifidobacteria have long been predominantly considered to be cysteine auxotrophs, we showed that this is not necessarily the case.

Bifidobacterium bifidum OLB6378 (OLB6378) was selected as a strain that enhances the production of secretory immunoglobulin A (IgA) in vitro. This ability of non-live OLB6378 has been shown by a clinical trial in preterm infants. In the present study, we examined whether non-live OLB6378 also enhances the production of secretory IgA, even in full-term infants. One hundred full-term infants were allocated to receive formula with (BbF group, 49 infants) or without non-live OLB6378 (PF group, 51 infants). Breastfeeding was prioritised, so infant formula was used for infants with breastfeeding difficulties. The intervention was initiated by five days of age. The faecal IgA concentration and OLB6378 level were determined at one, two, four, and eight weeks of age. Faecal IgA in the BbF group (1.04 ± 0.47 mg/g of faeces, n=45) was significantly higher than that in the PF group (0.85 ± 0.42 mg/g of faeces, n=49) at four weeks of age (p=0.047). OLB6378 was not detected in faeces at any age. This indicated that production of secretory IgA in full-term infants may also be enhanced by non-live OLB6378 intake.

Aging is recognized as a common risk factor for many chronic diseases and functional decline. The newly emerging field of geroscience is an interdisciplinary field that aims to understand the molecular and cellular mechanisms of aging. Several fundamental biological processes have been proposed as hallmarks of aging. The proposition of the geroscience hypothesis is that targeting holistically these highly integrated hallmarks could be an effective approach to preventing the pathogenesis of age-related diseases jointly, thereby improving the health span of most individuals. There is a growing awareness concerning the benefits of the prophylactic use of probiotics in maintaining health and improving quality of life in the elderly population. In view of the rapid progress in geroscience research, a new emphasis on geroscience-based probiotics is in high demand, and such probiotics require extensive preclinical and clinical research to support their functional efficacy. Here we propose a new term, "gerobiotics", to define those probiotic strains and their derived postbiotics and para-probiotics that are able to beneficially attenuate the fundamental mechanisms of aging, reduce physiological aging processes, and thereby expand the health span of the host. We provide a thorough discussion of why the coining of a new term is warranted instead of just referring to these probiotics as anti-aging probiotics or with other similar terms. In this review, we highlight the needs and importance of the new field of gerobiotics, past and currently on-going research and development in the field, biomarkers for potential targets, and recommended steps for the development of gerobiotic products. Use of gerobiotics could be a promising intervention strategy to improve health span and longevity of humans in the future.

Lactobacillus acidophilus surface layer proteins (SLPs) self-assemble into a monolayer that is non-covalently bound to the outer surface of the cells. There they are in direct contact with the environment, environmental stressors and gut components of the host in which the organism resides. The role of L. acidophilus SLPs is not entirely understood, although SLPs seem to be essential for bacterial growth. We constructed three L. acidophilus L-92 strains, each expressing a mutant of the most abundant SLP, SlpA. Each carried a 12-amino acid c-myc epitope substitution at a different position in the protein. A strain was also obtained that expressed the SlpA paralog SlpB from an originally silent slpB gene. All four strains behaved differently with respect to growth under various stress conditions, such as the presence of salt, ox gall or ethanol, suggesting that SlpA affects stress tolerance in L. acidophilus L-92. Also, the four mutants showed differential in vitro binding ability to human host cell proteins such as uromodulin or dendritic cell (DC)-specific intercellular adhesion molecule-3 grabbing non-integrin (DC-SIGN). Furthermore, co-culture of murine immature DCs with a mutant strain expressing one of the recombinant SlpA proteins changed the concentrations of the cytokines IL-10 and IL-12. Our data suggest that SlpA and SlpB of L. acidophilus participate in bacterial stress tolerance and binding to uromodulin or DC-SIGN, possibly leading to effective immune-modification.

This study aimed to reveal the differences in intestinal microbes in osteoporotic rats. The rats were divided into two groups: the control and OP (osteoporosis) groups (n=6). Days 0 and 70 were set as the time points. The rats in the OP group underwent bilateral ovariectomy (OVX). Differences between the control and OP groups were determined by 16S rDNA analysis. The relative abundances of OTUs and alpha/beta diversities were determined at days 0 days and 70. The abundances of Verrucomicrobia at the phylum level and Aerococcus, Coprobacillus, Veillonella, Anaerobiospirillum, Flavobacterium, Comamonadaceae, Ohtaekwangia, etc., at the genus level were found to be different between the control_70d and OP_70d groups. KEGG ontology analysis showed that the function of lipid metabolism could be related to OP. The 16S rDNA analysis in the OP rats revealed that intestinal microbes take part in the processes of OP and could affect lipid metabolism. Further study of the relationship between OP and intestinal microbes is necessary, and the prospect for intestinal microbes is a potential treatment for OP.

Lactic acid bacteria (LAB) are safe microorganisms that have been used in the processing of fermented food for centuries. The aim of this study was to isolate Lactobacillus from fresh tea leaves and examine the impact of an isolated strain on intestinal barrier integrity. First, the presence of Lactobacillus strains was investigated in fresh tea leaves from Kagoshima, Japan. Strains were isolated by growing on De Man, Rogosa and Sharpe (MRS) agar medium containing sodium carbonate, followed by the identification of one strain by polymerase chain reaction (PCR) and pheS sequence analysis, with the strain identified as Lactiplantibacillus plantarum and named L. plantarum LOC1. Second, the impact of strain LOC1 in its heat-inactivated form on intestinal barrier integrity was investigated. Strain LOC1, but not L. plantarum ATCC 14917^T or L. plantarum ATCC 8014, significantly suppressed dextran sulfate sodium (DSS)-induced decreases in transepithelial electrical resistance values of Caco-2:HT29-MTX 100:0 and 90:10 co-cultures. Moreover, in Caco-2:HT29-MTX co-cultures (90:10 and 75:25), levels of occludin mRNA were significantly increased by strain LOC1 compared with untreated co-cultures, and strain LOC1 had higher mRNA levels of MUC2 and MUC4 mucins than L. plantarum ATCC 14917^T and L. plantarum YT9. These results indicate that L. plantarum LOC1 may be used as a safe probiotic with beneficial effects on the intestinal barrier, suggesting that fresh tea leaves could be utilized as a safe source for isolating probiotics.

We report the isolation of bacteria capable of degrading milk oligosaccharides from suckling infant rats. The bacteria were successfully isolated via a selective enrichment method, in which the serially diluted intestinal contents of infant rats were individually incubated in an enrichment medium containing 3'-sialyllactose (3'-SL), followed by the isolation of candidate strains from streaked agar plates and selection of 3'-SL-degrading strains using thin-layer chromatography. Subsequent genomic and phenotypic analyses identified all strains as Enterococcus gallinarum. The strains were capable of degrading both 3'-SL and 6'-SL, which was not observed with the type strain of E. gallinarum used as a reference. Furthermore, a time-course study combining high-performance anion-exchange chromatography with pulsed amperometric detection revealed that the representative strain AH4 degraded 3'-SL completely to yield an equimolar amount of lactose and an approximately one-fourth equimolar amount of sialic acid after 24 hr of anaerobic incubation. These findings point to a possibility that the enterococci degrade rat milk oligosaccharides to "cross-feed" their degradants to other members of concomitant bacteria in the gut of the infant rat.

We investigated the gut microbiota in patients with non-alcoholic fatty liver disease (NAFLD) and its correlation with fibrosis and steatosis stratified by body mass index, as reflected in the controlled attenuation parameter and transient elastography values. A cross-sectional study was performed on 37 patients with NAFLD at Cipto Mangunkusumo National General Hospital from December 2018 to March 2019. The gut microbiota was investigated in fecal samples with 16S RNA sequencing using the MiSeq next-generation sequencing platform (Illumina). NAFLD was more common in patients with metabolic syndrome. Firmicutes, Bacteroidetes, and Proteobacteria were the predominant phyla. Bacteroides was more dominant than Prevotella, contrary to the results of previous studies on healthy populations in Indonesia. Microbiota dysbiosis was observed in most samples. The gastrointestinal microbiota diversity was significantly decreased in patients with NAFLD, high triglyceride levels, and central obesity. The Firmicutes/Bacteroidetes ratio correlated with steatosis and obesity, whereas some of the other species in lower taxonomy levels were mostly associated with steatosis and obesity without fibrosis. Proteobacteria was the only phylum strongly correlated with fibrosis in patients with an average body mass index. The gut microbiota diversity was decreased in patients with NAFLD, high triglyceride levels, and central obesity, and certain gut microbes were correlated with fibrosis and steatosis.